An elliptical is a fitness device involving both legs and arms, supposedly giving healthier movement while exercising, compared to a stepper or running strip.
I used part 12799 (spring loaded engine of 42046 Getaway racer) to provide resistance when using the elliptical. However, the curse of the device is that after a few turns it will throw you out - violently.
This is not an alternate build of 42046, but except for a few frictionless pegs, all parts come from that model. It can actually be built as an alternate - by replacing the front axle with a longer one and replacing the frictionless baige pegs with the blue ones. I suspect it will not work as well, though.
Enjoy, Comments and suggestions very welcome